Update. With the information y'all gave me I looked in the owner's manual and luckily my late sister-in-law wrote down the radio code. Although again the radio won't come up with Enter Code on the display, it's blank and nothing happens. It did come up when my wife drove it. Went to Auto Zone for a new battery tonight, reasoning that the old one was weak from being dead. Auto Zone guy did say that they can go into anti-theft mode when the battery goes completely dead. So far with the new battery the radio still isn't giving me Enter Code but maybe if it sits all night with a fresh battery it will work. I may drive it to work tomorrow and see if that helps.